Previous research has focused primarily on the neurophysiological properties of olfactory receptor neurons. As a result of this research, it became clear that other cells in the olfactory mucosa influence the response properties of the receptor neurons. These cells are the secretory elements in the olfactory mucosa, the sustentacular cells and the acinar cells of the olfactory glands. It is the long-term aim of this laboratory to investigate the integrated physiological activity of the vertebrate olfactory mucosa including the contribution of the secretory cells. The specific aim of the proposed experiments is to investigate the odorant and neuropharmacological regulation of secretion in the sustentacular cells and the acinar cells of the olfactory glands. The short-term objectives to be accomplished within the next five years are: a. to investigate the adrenergic regulation of glandular secretion using neuropharmacological and computer-assisted morphometric techniques, b. to identify the adrenergic innervation of the olfactory glands and/or the capillary vasculature using fluorescence histochemical techniques, c. to study the odorant regulation of secretion using light microscopic techniques, d. to characterize the cytological manifestations of secretory activity using transmission electron microscopic techniques and e. to investigate the physiological properties of secretion in short-circuit current studies employing an Ussing chamber-type preparation. The results of the proposed experiments will establish the cellular basis for the regulation of secretion on which to study the integrated physiological activity of the olfactory mucosa including that of the olfactory receptor neurons and the prereceptor events in vertebrate olfaction. The neuropharmacological studies in particular are directly relevant to clinical trials of drug treatment for rhinorrhea and peripheral rhinitis.